Question

我划分了一个有大量行的表，现在我有16个具有相同结构的表。当我试图在其中一个表格中找到某些内容时它很有效，但是当我不知道它应该在哪里时，我必须在所有表格中搜索它。

我这样做：

SELECT id, name, surname, age, sex, telephon, fax, email
FROM
    `out_sim_valuesmatrix_ep_ma13_1_16`,
    `out_sim_valuesmatrix_ep_ma13_2_16`,
    `out_sim_valuesmatrix_ep_ma13_3_16`,
etc
`    out_sim_valuesmatrix_ep_ma13_16_16`
WHERE
    `appln_idNum1` IN (24842422,24918676,24771783,24908804,24960166,25041955,25017764,25104985,25039175,25089121,24897200,25038905,24907508,24856413,24856413,25001485,24873551,24873551,24747119,25055354,25068104,24969433,24736299,24908799,24947820,24861202,24861202,25101573,24811406,24811406,24939062,25072049,24899024,24908795,25045775,24741197,25033220,24862936,24862936,24926838,24872619,24872619,25011020,24791353,24791353,24983796,24975187,25087564,25044301,24969428,24941046,24944919,24835727,24835727,25015010,25001957,24976200,25057258,25064419,25040849,25063554,25061255,24863241,24863241,24749445,24885880,24751246,24882026,25095717) // Here there are actually 1000 values!!!

然后我收到以下消息：

#1052 - Column 'appln_idNum1' in where clause is ambiguous

我该如何编写查询以找到正确的值？

当我这样做https://stackoverflow.com/a/409720/3499881时，在收到答案之前它很慢。

这个https://stackoverflow.com/a/21260560/3499881不是一个好的解决方案，因为我的选择应该有16 * 8行[16个表* 8列]。我认为这太过分了，不是吗？

还有其他可能性吗？

非常感谢提前!!!

Answer 1

如果表具有相同的结构，那么您希望使用union all，而不是from子句中的逗号：

SELECT id, name, surname, age, sex, telephon, fax, email
FROM (select * from `out_sim_valuesmatrix_ep_ma13_1_16` union all
      select * from `out_sim_valuesmatrix_ep_ma13_2_16` union all
      select * from `out_sim_valuesmatrix_ep_ma13_3_16` union all
      . . .
      select * from `out_sim_valuesmatrix_ep_ma13_16_16`
     ) t
WHERE
    `appln_idNum1` IN (24842422,24918676,24771783,24908804,24960166,25041955,25017764,25104985,25039175,25089121,24897200,25038905,24907508,24856413,24856413,25001485,24873551,24873551,24747119,25055354,25068104,24969433,24736299,24908799,24947820,24861202,24861202,25101573,24811406,24811406,24939062,25072049,24899024,24908795,25045775,24741197,25033220,24862936,24862936,24926838,24872619,24872619,25011020,24791353,24791353,24983796,24975187,25087564,25044301,24969428,24941046,24944919,24835727,24835727,25015010,25001957,24976200,25057258,25064419,25040849,25063554,25061255,24863241,24863241,24749445,24885880,24751246,24882026,25095717)

,执行所有表格的笛卡尔积，这是很多浪费的努力。您只需要所有行，因此请使用union all。

在具有相同结构的许多mySql表中搜索数据

1 个答案: